<?php /* Copyright (c) 2024 Freya Murphy */
class Loader {

	// keep track of what has been loaded
	private array $loaded;

	// the database
	private ?DatabaseHelper $db;

	function __construct() {
		$this->loaded = array();
		$this->db = NULL;
	}

	/**
     * Loads a $type of object from a $dir with a given $name
	 * @param string $name - the name of the object to load
	 * @param string $dir - the directory theese objects are stored in
	 * @param string $type - the type of the object
	 */
	private function load_type($name, $dir, $type): object|NULL {
		$path = $dir . '/' . $name . '.php';
		if (array_key_exists($path, $this->loaded)) {
			return $this->loaded[$path];
		}

		if (!file_exists($path)) {
			return NULL;
		}

		$parts = explode('/', $name);
		$part = end($parts);
		$class = ucfirst($part) . '_' . $type;
		require($path);

		$ref = NULL;
		try {
			$ref = new ReflectionClass($class);
		} catch (Exception $_e) {}

		if ($ref === NULL) {
			return NULL;
		}

		$obj = $ref->newInstance($this);
		$this->loaded[$path] = $obj;

		return $obj;
	}

	/**
	 * Loads a model
	 * @param string $name - the name of the model to load
	 */
	public function model($name): object|NULL {
		$root = $GLOBALS['webroot'];
		$dir = $root . '/_model';
		return $this->load_type($name, $dir, 'model');
	}

	/**
	 * Loads a controller
	 * @param string $name - the name of the controller to load
	 */
	public function controller($name): Controller|NULL {
		$root = $GLOBALS['webroot'];
		$dir = $root . '/_controller';
		return $this->load_type($name, $dir, 'controller');
	}

	/**
	 * Loads the given common lang
	 */
	public function lang(): void {
		$dir = $GLOBALS['webroot'] . '/lang/';
		$lang = $GLOBALS['lang'];
		if ($handle = opendir($dir)) {
			while (false !== ($entry = readdir($handle))) {
				if ($entry === '.' || $entry === '..' || $entry === 'apps') {
					continue;
				}
				$path = $dir . $entry;
				require($path);
			}
		}
		$GLOBALS['lang'] = $lang;
	}

	/**
	 * Loads a given app specific lang
	 * @param string $name - the name of the app
	 */
	public function app_lang($name): void {
		$dir = $GLOBALS['webroot'] . '/lang/apps/';
		$file = $dir . $name . '.php';
		if (file_exists($file)) {
			$lang = $GLOBALS['lang'];
			require($dir . $name . '.php');
			$GLOBALS['lang'] = $lang;
		}
	}

	public function db(): DatabaseHelper {
		if ($this->db) {
			return $this->db;
		} else {
			$this->db = new DatabaseHelper();
			return $this->db;
		}
	}

}